In the previous post I mentioned how Dennis Farina couldn't possibly have been as nasty as his usual movie persona, otherwise he wouldn't have gotten so many roles.
The best example I've ever seen of this dichotomy is probably Ving Rhames. Rhames almost always plays a prototypical black badass; perhaps his best known role was Marcellus Wallace, in Pulp Fiction.
Rhames got a Golden Globe in 1998 for Best Actor in a Television Production for his portrayal of Don King. He got up on stage, started crying, and asked Jack Lemmon -- another nominee -- to come up on stage so he could in turn give the award to him, as the man who really deserved it. It was the most un-Ving Rhames like performance you could possibly have imagined. Marcellus, to be honest, would certainly have been embarrassed.
But it explains why Rhames has gotten so many roles -- he's likable.